Knowing how to punctuate properly is essential to good legal writing. Besides the semicolon, though, lawyers probably misunderstand—and as a result misuse—the em dash more than any other punctuation mark. That’s because it’s possible for a lawyer to write for an entire career without ever having to use it.

But lawyers who consciously avoid using the em dash forsake an important legal-writing tool. They’re like carpenters who choose to work with rudimentary tools instead of precision instruments. The job gets done; but the result is hardly refined. . . .